24 research outputs found
Crystal-field mediated electronic transitions of EuS up to 35 GPa
An advanced experimental and theoretical model to explain the correlation between the electronic and local structure of Eu2+ in two different environments within a same compound, EuS, is presented. EuX monochalcogenides (X: O, S, Se, Te) exhibit anomalies in all their properties around 14 GPa with a semiconductor to metal transition. Although it is known that these changes are related to the 4f75d0 → 4f65d1 electronic transition, no consistent model of the pressure-induced modifications of the electronic structure currently exists. We show, by optical and x-ray absorption spectroscopy, and by ab initio calculations up to 35 GPa, that the pressure evolution of the crystal field plays a major role in triggering the observed electronic transitions from semiconductor to the half-metal and finally to the metallic state
Planck early results. XIII. Statistical properties of extragalactic radio sources in the Planck Early Release Compact Source Catalogue
The data reported in Planck’s Early Release Compact Source Catalogue (ERCSC) are exploited to measure the number counts (dN/dS) of
extragalactic radio sources at 30, 44, 70, 100, 143 and 217 GHz. Due to the full-sky nature of the catalogue, this measurement extends to the
rarest and brightest sources in the sky. At lower frequencies (30, 44, and 70 GHz) our counts are in very good agreement with estimates based on
WMAP data, being somewhat deeper at 30 and 70 GHz, and somewhat shallower at 44 GHz. Planck’s source counts at 143 and 217 GHz join
smoothly with the fainter ones provided by the SPT and ACT surveys over small fractions of the sky. An analysis of source spectra, exploiting
Planck’s uniquely broad spectral coverage, finds clear evidence of a steepening of the mean spectral index above about 70 GHz. This implies
that, at these frequencies, the contamination of the CMB power spectrum by radio sources below the detection limit is significantly lower than
previously estimated
Planck 2015 results XXVI. The Second Planck Catalogue of Compact Sources
The Second Planck Catalogue of Compact Sources is a list of discrete objects detected in single-frequency maps from the full duration of the Planck mission and supersedes previous versions. It consists of compact sources, both Galactic and extragalactic, detected over the entire sky. Compact sources detected in the lower frequency channels are assigned to the PCCS2, while at higher frequencies they are assigned to one of two subcatalogues, the PCCS2 or PCCS2E, depending on their location on the sky. The first of these (PCCS2) covers most of the sky and allows the user to produce subsamples at higher reliabilities than the target 80% integral reliability of the catalogue. The second ( PCCS2E) contains sources detected in sky regions where the diffuse emission makes it difficult to quantify the reliability of the detections. Both the PCCS2 and PCCS2E include polarization measurements, in the form of polarized flux densities, or upper limits, and orientation angles for all seven polarization-sensitive Planck channels. The improved data-processing of the full-mission maps and their reduced noise levels allow us to increase the number of objects in the catalogue, improving its completeness for the target 80% reliability as compared with the previous versions, the PCCS and the Early Release Compact Source Catalogue (ERCSC)
VizieR Online Data Catalog: Second Planck Catalogue of Compact Sources (PCCS2) (Planck+, 2016)
The Low Frequency Instrument (LFI) DPC produced the 30, 44, and 70GHz maps after the completion of eight full surveys (spanning the period 12 August 2009 to 3 August 2013). In addition, special LFI maps covering the period 1 April 2013 to 30 June 2013 were produced in order to compare the Planck flux-density scales with those of the Very Large Array and the Australia Telescope Compact Array, by performing simultaneous observations of a sample of sources over that period. The High Frequency Instrument (HFI) DPC produced the 100, 143, 217, 353, 545, and 857GHz maps after five full surveys (2009 August 12 to 2012 January 11). (16 data files)
Planck 2015 results I. Overview of products and scientific results
The European Space Agency's Planck satellite, which is dedicated to studying the early Universe and its subsequent evolution, was launched on 14 May 2009. It scanned the microwave and submillimetre sky continuously between 12 August 2009 and 23 October 2013. In February 2015, ESA and the Planck Collaboration released the second set of cosmology products based on data from the entire Planck mission, including both temperature and polarization, along with a set of scientific and technical papers and a web-based explanatory supplement. This paper gives an overview of the main characteristics of the data and the data products in the release, as well as the associated cosmological and astrophysical science results and papers. The data products include maps of the cosmic microwave background (CMB), the thermal Sunyaev-Zeldovich effect, diffuse foregrounds in temperature and polarization, catalogues of compact Galactic and extragalactic sources (including separate catalogues of Sunyaev-Zeldovich clusters and Galactic cold clumps), and extensive simulations of signals and noise used in assessing uncertainties and the performance of the analysis methods. The likelihood code used to assess cosmological models against the Planck data is described, along with a CMB lensing likelihood. Scientific results include cosmological parameters derived from CMB power spectra, gravitational lensing, and cluster counts, as well as constraints on inflation, non-Gaussianity, primordial magnetic fields, dark energy, and modified gravity, and new results on low-frequency Galactic foregrounds
Comment on "Mechanisms for pressure-induced isostructural phase transitions in EuO"
Comment on Jacques K. Desmarais, Alessandro Erba, Yuanming Pan, Bartolomeo Civalleri, and John S. Tse. Phys. Rev. Lett. 126, 196404 (2021
Hiperlipidemia familiar combinada: documento de consenso
La hiperlipidemia familiar combinada (HFC) es un trastorno muy frecuente asociado a enfermedad coronaria prematura. Se transmite de forma autosómica dominante, aunque no existe un gen único asociado al trastorno. El diagnóstico se realiza mediante criterios clínicos, y son importantes la variabilidad del fenotipo lipídico y la historia familiar de hiperlipidemia.
Es frecuente la asociación con diabetes mellitus tipo 2, hipertensión arterial y obesidad central. Los pacientes con HFC se consideran de riesgo cardiovascular alto y el objetivo terapéutico es un colesterol-LDL < 100 mg/dl, y < 70 mg/dl en presencia de enfermedad cardiovascular establecida o diabetes mellitus. Los pacientes con HFC requieren tratamiento con estatinas potentes y, a veces, tratamiento combinado. La identificación y el manejo de otros factores de riesgo cardiovascular, como la diabetes y la hipertensión, son fundamentales para reducir la carga de enfermedad cardiovascular. Este documento proporciona recomendaciones para el diagnóstico y el tratamiento integral de los pacientes con HFC especialmente dirigidas a médicos de atención primaria
Clinical and molecular characteristics of homozygous familial hypercholesterolemia patients: Insights from SAFEHEART registry
Homozygous familial hypercholesterolemia (HoFH) is a rare genetic disorder associated with very high levels of cholesterol, accelerated atherosclerosis and very premature death, often secondary to occlusion of the coronary ostia by supravalvular atheroma in untreated individuals.
To describe molecular and clinical characteristics of HoFH enrolled at SAFEHEART registry and to evaluate the role of the type of mutation in clinical expression.
SAFEHEART is a registry of molecularly defined familial hypercholesterolemia patients. A standardized phone call is made every year for the follow-up. Patients with confirmed HoFH were selected. Molecular and clinical characteristics were analyzed.
Thirty-four HoFH patients (27 true HoFH, 4 compound heterozygous familial hypercholesterolemia, and 3 autosomal recessive hypercholesterolemia) have been enrolled in the period 2004-2015. Twenty different mutations in LDLR gene have been detected. Sixteen patients carry defective mutations (DMs), and 15 carry null mutations (NMs). Only patients with NMs met low-density lipoprotein cholesterol (LDL-C) criteria for clinical diagnosis. Patients with NMs had higher untreated LDL-C levels (P < .0001), more aortic valve stenosis (P < .05), and lower age at first cardiovascular event (P < .05) compared to patients with DMs. In the follow-up, 1 liver transplant patient died and 3 cases underwent revascularization procedures. Eight cases started LDL apheresis and 1 case had a liver transplant.
HoFH phenotypic expression is highly variable. These patients have high atherosclerotic coronary artery disease risk including aortic valve stenosis and do not achieve the LDL-C treatment goals with standard therapy
Predicting Cardiovascular Events in Familial Hypercholesterolemia: The SAFEHEART Registry (Spanish Familial Hypercholesterolemia Cohort Study).
Although risk factors for atherosclerotic cardiovascular disease (ASCVD) in familial hypercholesterolemia (FH) have been described, models for predicting incident ASCVD have not been reported. Our aim was to use the SAFEHEART registry (Spanish Familial Hypercholesterolemia Cohort Study) to define key risk factors for predicting incident ASCVD in patients with FH. SAFEHEART is a multicenter, nationwide, long-term prospective cohort study of a molecularly defined population with FH with or without previous ASCVD. Analyses to define risk factors and to build a risk prediction equation were developed, and the risk prediction equation was tested for its ability to discriminate patients who experience incident ASCVD from those who did not over time. We recruited 2404 adult patients with FH who were followed up for a mean of 5.5 years (SD, 3.2 years), during which 12 (0.5%) and 122 (5.1%) suffered fatal and nonfatal incident ASCVD, respectively. Age, male sex, history of previous ASCVD, high blood pressure, increased body mass index, active smoking, and low-density lipoprotein cholesterol and lipoprotein(a) levels were independent predictors of incident ASCVD from which a risk equation with a Harrell C index of 0.85 was derived. The bootstrap resampling (100 randomized samples) of the original set for internal validation showed a degree of overoptimism of 0.003. Individual risk was estimated for each person without an established diagnosis of ASCVD before enrollment in the registry by use of the SAFEHEART risk equation, the modified Framingham risk equation, and the American College of Cardiology/American Heart Association ASCVD Pooled Cohort Risk Equations. The Harrell C index for these models was 0.81, 0.78, and 0.8, respectively, and differences between the SAFEHEART risk equation and the other 2 were significant (P=0.023 and P=0.045). The risk of incident ASCVD may be estimated in patients with FH with simple clinical predictors. This finding may improve risk stratification and could be used to guide therapy in patients with FH. URL: http://clinicaltrials.gov. Unique identifier: NCT02693548